PKM and hepatocellular carcinoma: The western blotting results showed that overexpression of PKM2 in both HCC cell lines promoted the expression of HIF-1α, and knockdown of PKM2 decreased the HIF-1α levels (Fig. 4c), while the changes of PKM2 had no effect on the expression of HSP90, which was probably because HSP90 was not the target gene of PKM2 or HIF-1α (PB2 may influence the levels of HSP90 through unknown mechanisms in the study, for example, PB2 may influence the stability or the degradation of HSP90).